Underride type collisions are vehicular collisions in which a passenger vehicle or pedestrian collides with a larger vehicle such as a tractor-trailer truck or a single unit truck (SUT) in which the pedestrian or passenger vehicle moves to a position beneath the larger vehicle which is generally higher from the ground than most passenger vehicles. This type of collision can result in passenger compartment intrusion (PCI) into the smaller vehicle which often results in severe and/or fatal injuries to occupants of the passenger vehicles. In addition, pedestrians or bicyclists may become entrapped beneath a truck and come into contact with the wheels or underbody of the vehicle. Underride collisions can also occur when a passenger vehicle hits a rear bumper of a larger vehicle causing the rear bumper to collapse and allowing the passenger vehicle to move forward under the larger vehicle (e.g., under the rear of a commercial truck or trailer). In any case, the consequences of this type of accident are dire.
Currently, commercial trucks and trailers utilize so called “D.O.T. dock bumpers” or “underride protection bumpers” which are intended to prevent underride of a smaller vehicle from the rear. However, these bumpers have been shown to be inadequate—especially when a smaller vehicle collides with the commercial truck or trailer near either end of the bumper. Often these bumpers collapse or buckle or break on collision and fail to provide adequate protection against underride. In addition, commercial vehicles sold and operated in North America are not currently regulated for side impact guarding.